Swing-derrick for ships and the like



O. KAHRS.

SWING DERRICK FOR SHIPS AND THE LIKE. APPLICATION FILED JUNE 25, 1918.

1,330,077. Patented Feb. 10,1920.

f/r/en/or 0/50 KM/j UNITED STATES PATENT OFFICE.

OTTO KAHRS, OF GHRISTIANIA, NORWAY.

SWING-DERRICK FOR SHIPS AND THE LIKE.

Application filed June 25, 1918.

To all whom it may concern:

Be it known that I, O'r'ro KAHRs, a subject of the King of Norway, residing at Ohristiania, in the Kingdom of Norway, have invented certain new and useful Improvements in Swing- Derricks for Ships and the like; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention relates to swing derricks for ships and the like and has for its object to provide a derrick of this kind which may easily be mechanically driven even when mounted as an ordinary derrick on the mast.

The usual ships derricks are operated by means of ropes or wires fastened to the top of the derrick beam. The operation of the derrick in this manner is slow and clumsy one rope or wire on each side of the derrick beam being necessary each requiring a man for its operation. On the other hand an ordinary derrick crane is too heavy and expensive for installation and use in ordinary ships.

According to the present invention a segment shaped disk is mounted on the ordinary derrick trunnion fastened to the mast, said segment-shaped disk serving as a base plate for the derrick beam and being connected with a mechanical driving apparatus by means of which it may be turned upon its pivot. The derrick beam may'suitably consist of truss work or the like in order to obtain sufiicient lateral rigidity.

The circumference of the segment may be provided with teeth, so that it may be turned Specification of Letters Patent.

Serial No. 241,883.

by means of pinion, screw or the like driven from a suitable source of power.

On the drawing is diagrammatically illustrated a form of the invention.

1 is the mast on which is mounted the ordinary trunnion 2 for a derrick beam.

Trunnion 2 is connected with a segmentshaped disk 3 which serves as a supporting or base plate for the derrick beam 4. The latter may consist of truss work, as illustrated, or may be provided with wire stays or the like in order to obtain sufiicient lateral rigidity.

The segment on its circumference is provided wit teeth and is engaged by a screwor worm 5, so that it may be turned in both directions by means of handle 6 or any other known hand operated or mechanically driven mechanism.

Claim.

In a'swinging loading derrick for ships, the combination of an annular band for attachment to a mast of the ship and carrying a trunnion; a derrick boom; a segmentshaped derrick boom supporting member; means for pivotally connecting the boom to the supporting member; a bearing on said supporting member adapted to engage the trunnion on said annular band, whereby the supporting member may be swung about theaxis of said trunnion, said supporting member being cut away to permit th1s movement without interference with the mast; and

means mounted on the deck of the ship for rotating said supporting member.

In testimony that I claim the .foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

OTTO KAHRS.

Witnesses:

J. A. LORMAR, M. W. KAHRS.

Patented Feb. 10, 1920. 

